Projects / Programmes
Dynamics of complex nano-systems
January 1, 2015
- December 31, 2021
| Code |
Science |
Field |
Subfield |
| 1.02.00 |
Natural sciences and mathematics |
Physics |
|
| Code |
Science |
Field |
| P002 |
Natural sciences and mathematics |
Physics |
| Code |
Science |
Field |
| 1.03 |
Natural Sciences |
Physical sciences |
ultrafast real time dynamics of emergence, competing order parameters, control of phase transitions, hidden state switching, transport studies in metastable states, novel nanomaterials for electronics, synthesis and new materials, development of theory of functional inhomogeneous materials
Researchers (40)
Organisations (1)
| no. |
Code |
Research organisation |
City |
Registration number |
No. of publicationsNo. of publications |
| 1. |
0106 |
Jožef Stefan Institute |
Ljubljana |
5051606000 |
91,101 |
Abstract
The aim of the research programme is to investigate the nonequilibrium dynamics of nonlinear complex systems in condensed matter using a carefully chosen combination of experimental and theoretical methods.
The main original idea behind this research pioneered by our group is that non-ergodically freely-evolving systems reveal new physics compared with traditional experiments performed under ergodic conditions in which only one external parameter is controlled, such as temperature, pressure, external field etc.. In temporally evolving systems, the dynamics through symmetry-breaking transitions is mainly governed by one particular excitation, without interference from other excitations of the underlying vacuum (electrons, phonons, magnons). We will address fundamental questions on the effect of symmetry and fundamental interactions of underlying microscopic vacua on global emergent behaviour. This will give us new insight into the mechanisms leading to symmetry breaking, and open up new possibilities in the study of the behaviour of matter under nonequilibrium conditions. It also promises a new generation of electronic devices based on complex materials, particularly nonvolatile memories.
The main experimental focus is on novel ultrafast spectroscopy techniques, some of which have been developed by our group (three pulse “cosmic quench” experiments). These will be complemented by nanoelectronics experiments, particularly charge transport by a new and revolutionary multi-probe STM technique in combination with optical excitation.
The research team is rejuvenated with some new members, with fresh relevant experience to kick-start the new experimental techniques in the proposed programme.
Emphasis will be placed on new materials exhibiting emergent properties as a result of collective excitations, whose phase transitions between different ordered states can be investigated in real time. The systems of interest here are a) the charge-ordered systems: layered transition metal tri-tellurides with dichalcogenides and the quasi 1D chain systems, b) oxide and pnictide superconductors, c) systems with competing order: pnictides and rare-earth vanadates.
The expertise of the group will also be applied to research with more immediate practical application potential: electron relaxation dynamics in solar cell materials leading to improved solar cell efficiency and nanoscale transport studies in new nanostructures without photoexcitation.
A very important part of the group activity is synthesis of new materials displaying different functional properties relevant in the present context using different methods, including molecular beam epitaxy, which enables us to have state of the art new materials for study, and at the same time allows us to rapidly develop possible applications.
The experimental efforts will be supplemented by theoretical modeling of nonlinear system dynamics and ordering which is crucial in bringing the experimental work to a much higher level.
Significance for science
The programme is the continuation of a highly succesful research effort which ran from 2008-2013 on the “Dynamics of complex nanomater”. Judging by its publication record (including numerous papers in Science, Nature, PRL and other top journals), and its success in starting new research fields through procuring state of the art equipment from EU funds and other prestigious international funding (ERC advanced grant, Marie-Curie and other FP7 projects), its activities are highly regarded both in Slovenia and abroad. The group has found a successful recipe for performing exciting science, resting on the shoulders of a stream of students and a small-numbered well-coordinated seniour team.
Scientific impact
The study of the realtime evolution of systems through symmetry breaking transitions (SBTs) in condensed matter systems breaking different kinds of symmetries (spatial, gauge, timereversal etc.) by monitoring single particle and collective excitations has important consequences in the fundamental physics of temporally evolving systems. The analogy with cosmology (i.e. the Big Bang) is particularly pertinent, as discussed by Kibble, Zurek, Varma, Volovik etc.. Other systems are also of interest, such as SBTs which occur after collisions of elementary particles, typically discussed in terms of Ginzburg-Landau derived theories, such as the Standard model.
Wider afield, the physics of economic and sociological systems are obvious examples of systems undergoing SBTs in time. The importance of the current project is that one can chose different symmetries in different laboratory systems to mimic inaccessible or irreproducible SBTs, such as the Big Bang or stock market crashes. Emergence of different symmetries can thus be explored by choice of system, and significant analogies can be drawn. Thus analogies between vortices and domain walls with cosmic strings and branes can be drawn. Dark matter analogues are offered by weakly interacting bosonic excitations, particularly phonons.
The control of SBTs is of fundamental interest as a means of directing systems into hidden ordered states not reachable under ergodic conditions, opening a window into “parallel universes”. (The wider impact of the current research was presented in a TEDx talk (see http://www.youtube.com/watch? v=FnL7I6tESAs&sns=em).
The field is rapidly expanding and the first international conference on “Higgs bosons in condensed matter” will be organized by the Yuakawa Institute in Kyoto in 2014. Furthermore, our group has been trusted with the organization of international conference on Photoinduced Phase Transitions PIPT5 at Bled in June 2014, and the Flatlands beyond graphene conference in 2015, which reflects the respect our group commands in the field.
The proposed research also has a number of technology spinoffs. The first type comes from the underlying essential materials science which leads to new functionality of nanomaterials, which we have already demonstrated in the recent past (e.g. MoSI molecular wires in batteries, catalysis, recognitive sensor substrates and additives to lubricants). The understanding of photoexcited electron energy relaxation is directly relevant for understanding charge transfer dynamics and solar cell efficiency, and other functionalities. Preliminary success was demonstrated in a recently published paper, where an 18% improvement of efficiency was systematically observed. Since then, further improvements of up to 60% were observed, which is a remarkable achievement condsidering progress has typically been relatively slow, with typical improvements of the order 10% or less.
The second category of spin-offs are even more exciting and come from the photoinduced phase transitions themselves. Control of SBTs in time is very important in future electronics devices, particularly memory devices. A potentially revolutionary development is the use of photoinduced or current injection induced hidden state transitions (Stojchevska et al.,
Significance for the country
Introduction of new technologies and research fields
The research programme introduces a number of crossdisciplinary new technologies and a new and original research field to Slovenia, specifically time-resolved spectroscopy as a whole, nanoelectronics and nanolithography (both by electron beam and proprietary laser technology). Nanoscale FET device construction, molecular beam epitaxy (MBE) and atomic layer deposition (ALD) are new techniques in Slovenia, and are introduced for the first time. The development of The LT 4 probe STM/AFM/SEM facility with Omicron – is unique in the world.
Spinoffs
In the last 10 years, the group started two spinoff companies (Mo6 and NANOTUL). Experience suggests that new spinoff products and technologies can be expected to arise in the forthcoming period. The synthesis of transitionmetal oxides, carbides, chalcogenides and nitrides represents a very interesting field between chemical and physical sciences on one side and technological applications on the other. These compounds are important for a diverse range of technology, such as electronics, as lubricants, nanocomposites or for energy storage and conversion.
Another spinoff in the pipeline will be developing multichannel detectors for femtosecond spectroscopy, which is commercially interesting. Prototypes are currently being tested and used in a number of publications.
Facility management
The group is responsible for setting up and maintaining a number of research facilities: FIB- HRTEM dual beam instrument, ALD, MBE, AFM Raman, 4probe STM/AFM/SEM. The equipment has been defined and set up by our group, as a facility for use by both academia and industry and procured through European restructuring funds within the Centre of Excellence in Nanoscience and Nanotechnology Nanocenter. The Nanocenter is led by the PI of this research programme and the group is responsible also for training of external personnel within the Nanocenter.
Training of students for industry. The research field which has direct consequences for training top quality engineers for Slovenian high-added value industry (like LPKF, Helios, BSH BoshSiemens Hausgeräte, Xpand, Litostroj Power) or abroad (like IEE Luxemburg, Ilmenau University, Germany, German Research School for Simulation Science).
Industrial cooperation
Intense cooperation takes place with LPKF, a hightech medium size multinational company, developing the next generation of a laser lithography system (the current system, which was developed jointly with the Physics department at the University of Ljubljana is a marketed product). New nanomaterials, nanomateirals for composites are in use in paints and coatings industry (Helios d.d., Cinkarna Celje d.d.). We expect commercial results in the field of battery electrode nanomaterials, solar cell components and sensor devices (Kolektor/Nanotesla institute).
Prestige and international collaborations
The research group has a world leading position in the field, competing and/or collaborating with groups at leading universities such as UC Berkeley, Stanford University, Tokyo University and institutes such as Max Planck in Hamburg and MIT. The award of an ERC Advanced grant TRAJECTORY testifies to the quality of the group and its importance in promoting Slovenia worldwide as a scientifically and technologically advanced country. Our group is currently involved in a number of EU projects: ERC Advanced Grant, Marie Curie ITN, HINT EU project 7FP, several COST projects and bilateral projects. Research group has access to over 100 Slovene and international projects through CENN Nanocenter equipment. Especially important are the synergies within the framework of the projects developed with the partner institutions, such as TASC & Elettra Laboratories in Italy, Joanneum Research Institute and the University of Graz in Austria, the University of Oxford in the United Kingdom, and Stanford University in the USA, the Swiss Institute of Technology of Lausanne and ET
Most important scientific results
Annual report
2015,
interim report
Most important socioeconomically and culturally relevant results
Annual report
2015,
interim report
